免疫沉淀法测定乳酸脱氢酶同工酶1的研究

Determination of Isoenzyme 1 of Lactate Dehy-drogenase by an Immunoprecipitation Method.

应用免疫沉淀法测定了乳酸脱氢酶同工酶１（ＬＤ１）．血清与抗血清用量为１０：１，加入抗血清５ｍｉｎ后再加入与血清量相等的饱和硫酸铵溶液．离心后测定上清液中的ＬＤ．总酶活性在６１８Ｕ／Ｌ内线性关系良好．二份标本批内精度ＣＶ值分别为３．７６％和４．７０％，批间ＣＶ值为７．００％，免疫沉淀法与电泳法高度相关（ｎ＝２２，ｒ＝０．９７６）．７２例正常人ＬＤ参考值为１０２．３１±１６．４Ｕ／Ｌ，ＬＤ１为２３．６５±４．３９Ｕ／Ｌ，ＬＤ１／ＬＤ为２３．１２±３．８５％．免疫沉淀法的优点是特异性高，操作简单，可用于自动生化分析仪．精确度高，线性关系好，测定范围宽，是测定ＬＤ１的理想方法．

soenzyme 1 of lactate dehydrogenase (LD1)was measured by an immunoprecipitationmethod. The antibody to M subunit of LD wasadded to the patient’s serum and incubated for5 min,at room temperature. The ratio ofserum to antibody was 10:1.After incuba-tion,a saturated ammonium sulphate solutionwas added with the same volume as serum.Then.centrifuged to precipitate all M-contain-ing isoenzyme (LDZ LDS) as insoluble anti-gen-antibody complex. Determined the residu-al activity of LD in supernatant fluid. The re-lationship Between the LD activity and ab-sorbance was linear up to 618U/L.Within-runcoefficient of variation (CVs) of two sampleswere 3. 8% and 4. 7%. Day-to-day coefficientof variation(CVs)was 7.0%. The correlationof immunoprecipitation method and elec-trophoretic procedure were cinsistent (n=22,r=0. 976).Reference values for total LD andLD 1 were 102.3± 16.4U/L and 23.7±4.4U/L respectively.The ratio of LD1 to to-tal LD was 23.1±3. 9%. The advantages ofimmunoprecipitation method were:high speci-ficity.good precision and linearity, easy oper-ation.Immunoprecipitation method was verysuitable for measuring LD1 and could adapt-able to the automatic analyzer.